diff --git a/libc/arch-sh/syscalls/dup2.S b/libc/arch-sh/syscalls/dup2.S
new file mode 100644
index 0000000..da2b7bd
--- /dev/null
+++ b/libc/arch-sh/syscalls/dup2.S
@@ -0,0 +1,32 @@
+/* autogenerated by gensyscalls.py */
+#include <sys/linux-syscalls.h>
+
+    .text
+    .type dup2, @function
+    .globl dup2
+    .align 4
+
+dup2:
+
+    /* invoke trap */
+    mov.l   0f, r3  /* trap num */
+    trapa   #(2 + 0x10)
+
+    /* check return value */
+    cmp/pz  r0
+    bt      __NR_dup2_end
+
+    /* keep error number */
+    sts.l   pr, @-r15
+    mov.l   1f, r1
+    jsr     @r1
+    mov     r0, r4
+    lds.l   @r15+, pr
+
+__NR_dup2_end:
+    rts
+    nop
+
+    .align  2
+0:  .long   __NR_dup2
+1:  .long   __set_syscall_errno